Before writing a Python program to allow us to set the servo to an angle between 0 and 180, we can try some experiments in the Python Console.
To launch the Python Console type:
To launch the Python Console type:
# python Python 2.7.3 (default, Apr 3 2013, 21:37:23) [GCC 4.7.3 20130205 (prerelease)] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>>
First, we need to import the library, so enter the command:
>>> import Adafruit_BBIO.PWM as PWM
Now enter the commands below into the Python Console one at a time, and you should see the servo change position.
>>> PWM.start("P8_13", 95.0, 60) >>> PWM.set_duty_cycle("P8_13", 97.0) >>> PWM.stop("P8_13") >>> PWM.cleanup()
NOTE: If your servo doesn't move you might need to change the polarity of the PWM signal and try again. Add a 4th parameter to the PWM.start function with a value of 1 (one), this will invert the PWM signal so it's low when normally high and vice versa.
Here's the same code but with the inverse parameter set:
Here's the same code but with the inverse parameter set:
>>> PWM.start("P8_13", 95.0, 60, 1) >>> PWM.set_duty_cycle("P8_13", 97.0) >>> PWM.stop("P8_13") >>> PWM.cleanup()
Page last edited July 15, 2013
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